Injuries have forced Scotland coach Vern Cotter into four changes to his side ahead of tomorrow's clash with Tonga at Rugby Park.

The home of Kilmarnock will host the first ever major international Test to be played on a synthetic pitch.

Tight-head prop Geoff Cross and No.8 Johnnie Beattie come into the pack for Euan Murray and Adam Ashe, who miss out through thigh and neck injuries respectively.

In the backs, 90-cap Glasgow Warrior Sean Lamont, who came on against New Zealand as an injury replacement for crocked club-mate Mark Bennett, retains his place in midfield.

The final change sees Edinburgh Rugby's free-scoring winger Tim Visser make his first appearance since the summer tour in place of the injured Sean Maitland.

Cotter, whose sides have performed encouragingly in the five-try win over Argentina and narrow defeat to New Zealand this month, said: "We came very close to the best side in the world last Saturday.

"But when you look at the content of our performance and what the players did on the paddock, it'd be hard for any coach to be too unhappy. There were a lot of good things in the game and things we've looked to improve.

"They were naturally disappointed not to build on a good performance against Argentina, but they're setting standards for themselves, which I think is really important for moving forward.

"It is very encouraging and we'll continue to work hard on parts of our game to create pressure, momentum and points.

"To do that against an impressive Tongan team will present another big challenge for this group.

"The Pacific Islanders pride themselves on their physicality, power and pace, all of which combined to hurt Scotland at Pittodrie two years ago.

"We will have to be on top of our game to secure the win on Saturday."